In 1994 Christine Jones began the NSF-funded SAO Astronomy REU (Research Experience for Undergraduates) Program.
I was an advisor the first year, and helped out informally for several years before becoming a co-director. As of 2018 Matt Ashby took over from Christine as PI, and I remained co-director.
Each year we welcome about 10 undergraduate students from across the USA to the Harvard campus to provide them with experience in research and prepare them for grad school. (A few non-US students have also joined the program via other funding sources).
It's been an incredible experience - I am proud to have known these amazing scientists early in their careers and delighted that many of them are still my friends.